so basically you just need some kind of rack/enclosures? i think the cheapest way would just be to get those 6qt tubs and lay heat tape on a desk or something to set them on, im sure you could get that to work (if you have the space) untill you could build a rack, check CL for plywood, thers alway people on mine selling 4x8 sheets (the good stuff too)for like 10 bucks a peice, and since its only one female thats pregnant, im sure you could get away with 2 sheets max, maybe even just one